The best moisture meters

Moisture meters

A moisture meter is an ideal tool for locating hidden water leaks behind drywall and for checking moisture levels in wood and other materials. Here we will show you how to use them, explain the different types, and review the MMD4E, MMD7NP, and MMH800 moisture meters from General Tools.

Topics covered
  • Types of moisture meters
  • The General Tools MMD4E
  • The General Tools MMD7NP pinless
  • The General Tools MMH800 All-In-One
  • Comparison table

Types of moisture meters

When it comes to selecting a moisture meter, you will have three varieties to choose from. There are pin, pinless, and all-in-one types.

Pin-types: Pin-type moisture meters can be recognized by their dual pins. These pins penetrate the surface of the desired area you want to be tested. It only reads the moisture levels up to the point where the pins end. The reading level, which is given in %MC, is determined by the electrical resistance between the two pins. The pin type can provide readings on any surface they can penetrate; therefore, using a pinless version would be better for impenetrable surfaces.

Pinless types: Pinless moisture meters can detect moisture levels up to 1″ deep. They are ideal for measuring moisture levels behind bathroom tiles and various types of flooring. The only downsides are that it will give false readings on metal surfaces, and it will not be able to provide a reading unless the surface area is 100% flat. Also, if the surface area you are attempting to read is too thin (less than 1″) it will give you the moisture level reading of whatever sits behind it.

All-in-one types: The all in one type is the preferred version among building inspectors, IAQ, and flooring specialists as it’s capable of taking readings with and without pins.

How to pick the right drywall moisture meter

It only takes 1% moisture for standard drywall to start degrading, which is why regular monitoring of moisture levels is recommended. That doesn’t mean you can use any device because when it comes to drywall, the moisture meter you use must have a gypsum reading scale function or the ability to read low %MC levels. Also, you will want to choose a pinless type to prevent poking holes into the drywall you are testing.

The MMD7NP from General Tools is the perfect drywall moisture meter.

How to pick the right wood moisture meter

A wood moisture meter is a very handy tool as it can stop you from purchasing waterlogged wood and help you monitor the current moisture levels in your wooden furniture, wood floors, etc. Luckily, reading the moisture levels in wood is pretty straightforward, but you will have to choose between a pin or pinless type. The pinless type will allow you to take accurate readings on level wooden surfaces, but if the surface is not straight, then a pin-type will be a better option.

The MMH800 all-in-one from General Tools is the perfect wood moisture meter.

Moisture meter reviews

Below we will review three of the best value for many devices without compromising on quality. All three reviewed models are from General Tools.

The General Tools MMD4E Moisture Meter

The MMD4E Pin-type Moisture Meter fits comfortably in your hand and has an LCD screen to give you clear readings. The stainless steel pins will provide you with accurate readings on the moisture levels in sub-flooring, wood, concrete, and drywall.

The device even has a smart Bluetooth function that sends and stores readings straight to your smartphone for extra convenience. It’s a high-quality tool that enjoys consistently high ratings on and is one of the best pin-type moisture meters on the market.

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The General Tools MMD7NP Pinless Moisture Meter

The General Tools MMD7NP Pinless Moisture Meter tests for moisture levels up to 1″ deep without damaging surface areas with pins.

It’s ideal for use on all types of wood, drywall, and even masonry surfaces. Just like the MMD4E mentioned above, it also has a smart Bluetooth function that sends readings to an app on your smartphone. Its other features include a powerfully bright LCD screen so that you can clearly see readings from various angles, a low battery indicator, HOLD button, out of range alarm, and a handy auto power-off function to preserve battery life.

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The General Tools MMH800 All-In-One Moisture Meter

The General Tools MMH800 All-In-One Moisture Meter can be used as a pin-type and pinless moisture meter. It’s renowned for its incredible accuracy, and apart from being able to detect moisture levels, it also has the added ability to find the actual source of leaks.

The device comes with a host of additional features, such as the ability to check and display ambient temperatures and humidity in addition to a HOLD and auto power-off function. It’s the preferred moisture detector tool among many building inspectors and flood damage responders.

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Comparison table

Tool Size Weight Type Batteries Included
MMD4E 5.5 x 9.5 x 1.4 Inches 7.2 Ounces Pin Type Yes
MMD7NP 1.1 x 3 x 6.5 Inches 1.4 Ounces Pinless Yes
MMH800 3.6 x 8.1 x 12 Inches 2 Lbs All In One Yes